Highly loaded and thermally stable Cu-containing mesoporous silica-active catalyst for the NO + CO reaction

We report the synthesis of a highly loaded and thermally stable Cu-containing mesoporous silica, which was developed by making use of poly(acrylic acid) (Pac) assembled with surfactant (C(16)TAB), as template. On this backbone, TEOS and Cu(II) hydrolysis takes place leading to the development of the final mesostructure. Poly(acrylic acid) is used not only as a micelle structural component but also as a complexation agent for Cu(II) species resulting in high metal loading and increased thermal stability of the mesoporous network. The original uncalcined material possesses hexagonal ordering, while upon calcination it is transformed into a wormlike mesoporous network with metal loading >14 wt % Cu. An evaluation of its performance as heterogeneous catalyst in NO reduction by CO shows catalytic activity comparable with that of noble metal catalysts. Complete NO conversion, with >90% selectivity to N(2), was achieved between 190 and 200 degrees C. The material retained its structure and catalytic activity after 24-h testing at the maximum catalytic conversion of NO and CO.